Process of and apparatus for cracking petroleum.



F. C. RUFF. PROCESS OF AND APPARATUS FOR CRACKING PETROLEUM. APPLICATION FILED JAN. 15. 19H.

1 25,582. Patented Dec. 23, 1919.

In/entor EdRufi UNITED STATES PATENT OFFICE.

FREDERICK C. RUFF, OF LOS ANGELES, CALIFORNIA, ASSIGNOR T0 BY-PROIDUCTS MANUFACTURING COMPANY, OF SAN FRANCISCO, CALIFORNIA, A- CORPORA- TION OF CALIFORNIA.

PROCESS OF AND APPARATUS FOR CRACKING PETROLEUM.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Application filed January 15, 1917. Serial No. 142,542.

To all whom it may concern.-

Be it known that I, FREDERICK C. RUFF, a subject of the Emperor of Germany, re-

siding at Los Angeles, in the county of Los- Angeles and State of California, have invented new and useful Improvements in Processes of and Apparatus for Cracking Petroleum, of which the following is a specification.

The object of the present invention is to provide an improved process of, and apparatus for, cracking petroleum or fractions thereof to obtain therefrom condensable hydrocarbons, as gasolene or aromatic hydro carbons. The apparatus is the same, and the process is practically the same, for obtaining gasolene as for obtaining aromatic hydrocarbons, the differences being in the temperatures used andin the rates of supply of the petroleum or fraction.

In the accompanying drawing, the figure is a sectional view of my improved apparatus.

Referfing. to the drawing, 1 indicates a furnace having'therein a fluid fuel burner 2 and a coil of pipe 3. Petroleum supplied to said pipe 3 is heated to a temperature somewhat less than that at which it 'is cracked into carbon, heavy oils, condensable hydrocarbons, and fixed gases. After leaving said furnace said pipe passes through a wall of. a cracking chamber 4, preheated by an oil burner 5, the products of combustion escaping by a chimney 10 having thereln a valve 20. It will be understood that the cracking chamber is preheated before. the

actual operation of the device is instituted.

During this preheating the valve 20 is opened and the burner 5 ignited. When the cracking chamber is sufficiently preheated for correct operation the burner 5 is ex-- tinguished and the valve 20 closed. Said pipe 3 terminates in said cracking chamber opposite to the discharge end of a pipe 6. By said pipe 6 steam, or one of the fixed gases, as hydrogen, methane, ethane, or a mixture of any two or more of these, superheated to a temperature of from 1100 to 1600 F. is injected into said cracking chamber directly opposite to the point of discharge of the petroleum. Taking advantage of the catalytic quality of iron, and in order to divide the introduced petroleum into finely divided particles, the interior of the cracking chamber is provided with cast iron baflie plates 7. Iron checker bricks might also be used. By these means the petroleum and superheated gas (in which term' is here included steam) are intimately mixed. Thereby the temperature of the petroleum is raised to the point at which it is cracked with the production of gasolene or aromatic hydrocarbons.

If steam is used, and the temperature be so high that the steam is dissociated in the presence of the carbon of the crackedpetroleum, then the hydrogen of the steam partly combines with unsaturated hydrocarbons and partly passes .05 with the fixed gases andvapors to be used as fuel, and partly is recovered with oxygen as hot condensed water, which is separated fromthe oil, vaporized, and again superheated, while some oxygen combines with the free carbon to form carbon monoxid.

' It is known that if petroleum is cracked in an atmosphere containing certain fixed gases, then the tendency of the cracking process is .'to produce products other than said gases. Thus, if the gas introduced by the pipe 6 be hydrogen, then in the cracking of the petroleum there will be little tendency to obtain hydrogen, but the other products of cracking will be correspondingly increased. In the present instance, where it is desired to produce from the cracking of the petroleum condensable hydrocarbons, the

ably a mixture of the fixed gases resulting from the cracking of the petroleum, and preferably also in the same proportions as they wouldbe obtained from the petroleum. By this means as little as possible of the fixed gases are obtained .by the cracking of the petroleum and proportionately a greater amount of the condensable hydrocarbons. Of course, the fixed gases so introduced will be recovered, together with the additional fixed gases obtained by the cracking of the petroleum, and such fixed gases, or a proper portion of them, will be reheated to the desired temperature, and reintroduced by, the pipe 6 into the cracking chamber.

In case a fraction should be used evaporating up to 400 F., the operation is carplete at a temperature of from 1100 to 1600 F. But, in case crude oil, or reslduum, or any other fraction boiling above 400 F., is used, then the first operation would result in obtaining a greater percentage of light oils boiling up to 400 F., and 1t 1s then necessary to repeat the operation with the latter light oils. This repetition is necessary because, in the first operation, some of the oils would not be converted into aromatic oils except under the perfect conditions, which in practice cannot be insured, and therefore it is preferable to perform the operation twice. In the latter case, the 011 is first thoroughly cracked and the heavy asphaltic-like residuum is separated on the bottom of the cracking chamber. This heavy residuum is suitable for the manufacture of coke.

The operation is assisted by the injection of the superheated steam or fixed gases by pipes 9 entering the cracking chamber at points above the entrance of the petroleum, these pipes 9 furnishing additional heat in the ascent of the petroleum vapors to crack athe same into the solid, liquid and gaseous products.

The hot vapors and fixed gases pass over by a pipe 11 leading into a washer 12,'into the lower portion of which lead the hot heavy oils y a pipe 13 leading from the bottom of the. cracking chamber. These oils are still so hot that the vapors of the condensable gases can be passed therethrough without being condensed. Said vapors escape by a pipe 15 having therein a valve 16, together with the heavy oils which are separated by any suitable means. Inorder to secure a uniform product and the highest possible yield of aromatic hvdrocarbons, the

' conversion takes place under pressure, which pressure is produced by means of the throttle valve 16 on the nine 15.

By passing the vapors of the condensable hydrocarbons through the washer, any free carbon that may have been carried over with by the heavy oils through which said vapors and carbon are compelled to pass.

It should be noted that the petroleum passing through the preheating pipe 3 does not deposit any carbon therein, as the temper-ature therein, never reaches the point where the petroleum is decomposed. All the reactions take place in the cracking chamber, When the finely divided petroleum comes in intimate" contact with the steam or fixed gas or gases and the heat is there fore directly. applied through the. whole mass of petroleum, in contradistinction to other processes which are carried on in kettles or pipes and where the heat is externally applied. It is obvious that the external application of heat results in a zone of high temperature immediately adjacent to the walls of the container, the temperature gradually decreasing toward the interior of the container.

In converting petroleum into aromatic hydrocarbons, carbon is always separated, but where the cracking or converting operation takes place in pipes or kettles by means of the external application of heat, the separated carbon adheres firmly to the hot walls of the containers, forming a crust which gradually clogs up said containers. This clogging up is avoided by my process, where the heat is directly applied and evenly distributed to the hydrocarbons within .the container. The separated carbon does not form a coating on the walls of the container.

vapors and is afterward removed from the latter by washing.

In the ordinary operation there is no danger of the cracking chamber being clogged up through carbon deposits. However, should the chamber, through the negligence of the operator, become clogged up, an auxiliary cracking chamber which is preheated before being put in operation may be put in operation while the first one is burned out. This burning out does not injure the apparatus and the process of cracking is not interrupted.

In running quicker, so that not all the cracked petroleum is converted into aromatic hydrocarbons, some gasolene is formed, which can be separated in nitrating the aromatic oils and separating the same by gravity. As the aliphatic and naphthenic hydrocarbons are not attacked by mixed nitric and sulfuric acid at low temperatures, a perfectly suitable gasolene of high Baum can be separated.

the operation somewhat While I have shown the form of -appa-' ratus and process described, it will' be obVi-i that various changes in the details of conthe condensable hydrocarbons 1S taken up struction and in the steps of the process may be resorted to'without departing from the spirit of my invention as claimed.

I- claim z- 1. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, mixing it in the presence of a catalyzer in a closed chamber with steam heated to. a temperature above the cracking temperature, and passing the gaseous products through the residual liquid to washthe same.

2. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, mixing it in the presence of a catalyzer in a closed chamber with a fixed gas heated to a temperature above the cracking temperature, and passing the gaseous products through the residual liquid to Wash the same.

3. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, mixing it in the presence of a catalyzer in a closed chamber with steam heated to a temperature above the cracking temperature, separately drawing ofi the gaseous and liquid products, and passing the gaseous products through the liquid to wash the same.

4. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, mixing it in the presence ofa catalyzer in a closed chamber with a fixed gas heated to a temperature above the cracking temperature, separately drawing 05 the gaseous and liquid products, and passing the gaseous products through the liquid to wash the same.

5. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, then directing the petroleum so heated and steam, heated to a temperature above said cracking temperature, in opposite directions against one another, and passing the gases so obtained through the resulting liquid products while the latter are still at a temperature above the boiling point of the condensable hydrocarbons in said gaseous products.

6. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, then directing the petroleum so heated and a fixed gas, heated to a temperature above said cracking temperature, in opposite directions against one another, and passing the gases so obtained through the resulting liquid products while the latter are still at a temperature above the boiling point of the condensable hydrocarbons in said gaseous products.

7. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, then directing the petroleum so heated and steam, heated to a temperature above said cracking temperature, in opposite directions against one another, adding to the gaseous products of the mixture so formed additional quantities of steam so superheated, and passing the gaseous products through the liquid products while the latter are still at a temperature above the boiling point of the condensable hydrocarbons in said gaseous products.

8. The process of cracking petroleum which consists in preheating petroleum to a temperature somewhat less than its cracking temperature, then directing the petroleum so heated and a fixed gas, heated to a temperature above said cracking temperature, in opposite directions against one another, adding to the gaseous products of the mixture so formed additionalquantities of the fixed gas so superheated, and passing the gaseous products through the liquid products while the latter are still at a temperature above the boiling point of the condensable hydrocarbons in said gaseous products;

9. An apparatus for cracking petroleum or its fractions comprising a cracking chamber, a pipe for conducting steam or a fixed gas thereinto, a pipe for conducting petroleum thereinto, means for heating the latter pipe, catalyzing material in said cracking chamber above said pipes, a washer, a pipe leading from the bottom of the cracking chamber to the lower part of the washer,

and a pipe leading from the top of the.

cracking chamber to the washer.

10. An apparatus for cracking petroleum I or its fractions comprising a cracking chamber, a pipe for conducting steam or a fixed gas thereinto, a pipe for conducting petroleum thereinto, means for heating the latter pipe, catalyzing material in said cracking chamber above said pipes, branch pipes leading from the first-named pipe and discharging into the cracking chamber above the steam or fixed gas and petroleum pipes,

a washer, a pipe leading from the bottom of the cracking chamber to the lower part of the washer, and a pipe leading from the top of the cracking chamber to the washer.

11. An apparatus for cracking petroleum or its fractions comprising a cracking chamber, a pipe for conducting steam or a fixed gas thereinto, a pipe for conducting petroleum thereinto, means for heating the latter pipe, catalyzing material in said cracking chamber above said pines, a washer having an overflow pipe, and means for conducting the products of the cracked petroleum into the washer below the level of the liquid therein.

12. An apparatus for cracking petroleum. or its fractions comprising a cracking chamber, a pipe for conducting steam or a fixed gas thereinto, a pipe for conducting petroleum thereinto, means for heating the latter pipe, catalyzing material in said cracking chamber above said pipes, branch pipes leading from the first-named pipe and discharging into the cracking chamber above the steam or fixed gas and petroleum pipes, a washer having an overflow pipe, and means for conducting the products of the cracked petroleum into the washer below the level of the liquid therein. 

